Brachiosaurus

Brachiosaurus was built differently from most other giant sauropods. While animals like Diplodocus held their necks roughly horizontal, Brachiosaurus had front legs longer than its hind legs — like a giraffe — giving it a permanently upward-sloping posture and allowing it to browse at extreme heights. At full stretch, its head could reach nearly 13 meters off the ground.

For decades, scientists thought Brachiosaurus must have lived in water to support its enormous weight — the buoyancy hypothesis. We now know this was wrong. Its leg bones were fully capable of supporting it on land, and its nostrils and lungs were adapted for terrestrial breathing, not aquatic wading.

Brachiosaurus and the other Morrison Formation giants were ecological engineers on a vast scale. A herd of animals this size would have dramatically reshaped the landscape — knocking down trees, creating clearings, and opening up habitats for smaller animals.

Interestingly, the dinosaur you see in many museum mounts labeled 'Brachiosaurus' is actually Giraffatitan brancai — a closely related African species once thought to be the same animal. The two lived on the same continent before Gondwana began to split.